18z GFSP brings a decent cold spell lasting until the end of the year.

http://www.theweatheroutlook.com/twodata/datmdlout.aspx

Oh right, thanks 

I agree with Neil about the GFS 18z op run, it's sort of like a faded pair of jeans...

The GFSP 18z op run is more tune with other recent runs.

Neither are anything like the ECM 12z op run was in terms of LP undercutting the mid-Atlantic ridge. I wonder if ECM's tendency to over-amplify actually worked against a colder solution for once?

Earlier Matt Hugo reported that every single one of the 51 ECM ensemble members followed the op run in developing LP to the NW around 24th December. On the face of it that sounds terrible until you realise that a rapid transfer into the North Sea and then Scandinavia is the most likely way forward, as shown by the op run.

What I see to be of greater importance is whether LP will undercut that mid-Atlantic ridge or not, for which a later Tweet featuring a rare snapshot of the discussed ECM cluster has since revealed seemingly no support whatsoever (https://twitter.com/MattHugo81/status/544964810728042496).

The thing is though - having every single member fall into one cluster like that for 9 days range across the entire N. Atlantic sector is truly bizarre. In fact I wouldn't have thought it possible even at 4-5 days range, let alone 9!

One proposed explanation on another site that I've read is that the ECM ensembles sometimes play 'follow the op run' when faced with very high levels of uncertainty (while GEFS clearly isn't doing that!). Does anyone on here know how credible that idea is? Mainly out of interest really.

The presence of various 'odd' looking charts at the moment is something I remember from the modelling prior to December 2009's changes and the same for November 2010.

I also remember little pockets of higher heights appearing at the higher latitudes on the higher resolution runs (this sentence is really escalating! *tumbleweed*) that often made the difference between a breakdown and continued cold conditions, and a few recent op runs have come up with these, which is nice (nothing more at this point - just nice).

Anyway, the GFSP 18z is great fun to look at, as Brian has just posted right on cue - great minds eh Brian?

High Leigh, sorry I didn't notice your question until just now.

Generally speaking, you can right-click on an image and select 'copy image' (not 'copy link' or 'copy URL' - that's for posting links to charts) or whatever the equivalent is in your browser, then use the usual shortcut of holding down ctrl and tapping on 'v' to paste the image straight into your post.

It's then a good idea to resize it (click on bottom-right corner and drag) so that the larger dimension is '500' or less, for ease of viewing.

Hope that helps, if not feel free to PM me 

Thought I'd look at the GFSP (I know it says GFS still, my script isn't advanced enough to change that yet). Things continue to look interesting, and the theme of a midatlantic high continues. At 240hr we see cold air starting to push in.

I would have thought that stuff on the northern edge of the low would be snow.

It is actually showing snow on its northern edge when one zooms in which is difficult to do here, the link to the full sized version is:

http://tinypic.com/view.php?pic=2qce5cn&s=8#.VJDF2CtpTt8

This is using the built in precip type that the GFS uses like wetter3 or TWO (incidentally you would not believe how much of a nightmare it is to try and create this, its almost as if the thing is designed to make you tare your hair out; took me hours to work out how to deal with the boundaries between the precip types). It also shows freezing rain (red) and sleet (yellow) though tbh it never shows anything, I'm starting to think they are duds.  

Why is everyone so pesimistic? The pattern we are being offered at the moment is (at the absolute least) extremely interesting. Far more interesting than we have seen for weeks if not months. What I don't get is that people were seeing potential at the start of the month when nothing non-zonal was being offered at all, yet now something really is stiring, and people seem even more pessimistic. I really want to know what I'm missing here, that greenland high has come out of low res into high res and has been there consistently for 3 days on every single GFS/GFSP run, now the ECM is on board too! 

A quick rundown of last night's ECM control:

240: Low west of UK, 850s from -8C over northern Scotland to +8C over Cornwall

288: Elongated low to SW of UK, warm front over northern England. 850s from -9C over Scotland to +7C over Cornwall

336: Low over Kent, northerlies over most of the UK. 850s from -10C over northern Scotland to +1C south of the M4

360: Low fills over the Netherlands, col over Northern Ireland, Wales and SW England, NNW'lies or NW'lies elsewhere. 850s below -5C except over the south of Cornwall.

FWIW, the "total frozen precipitation" chart shows Scotland plastered with snow by 360, with lesser amounts over Northern Ireland, Wales, NW England and SE England.

EDIT: How's this for a fun chart?

http://images.meteociel.fr/im/5347/gfs-2-276_use3.png

I sense there will be some excitement mounting today.

GFS 0z @240 hours

GFS Parallel 0z @ 240 hours

That's a good chart but the parallel run GFS charts later on deliver something even more spectacular - seems it wants a Christmas blizzard!

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=276&mode=0&runpara=1

I wonder if ECM will come on board today?  GEM shows another solution of a brief cold snap with high pressure nudging in too quickly killing the cold feed.Ironic as it's normally GEM which goes for the crazy charts yet here it's not:

http://www.meteociel.fr/modeles/geme_cartes.php?&ech=240&mode=0&carte=0

However all FI still and ECM was not on board last night, will it be this morning?  Could be this all flips back to a milder solution, but we could get even more interesting runs as we get into the weekend - one to watch and more runs needed as still too far away for my liking.

I had my eye on that particular chart too - what a stunner! 

So, ECM continues the theme of a cold burst post-Christmas, with the fun and games starting on Boxing Day. The battle-ground is right over the UK to start with, but then sinks southwards as lows deepen and run eastwards across the Atlantic. By the end of the run the whole of the UK is in cold air.

As the GFS(P) shows this morning, when you get deep Atlantic lows barging into cold air moving southwards there's the recipe for an absolute snowfest. The GFS(P) shows a foot of snow in SE England, for example, as a low engages the jet and deepens in just the right position to bring an exceptional snowfall.

The general pattern has remained the same for a few runs now, which is good news if you're a coldie. I expect the fun model-watching to continue for the next couple of days at least!

PS, WI - look at the 850s and then see that the angle of attack of that low is for it to move ENE'wards or eastwards rather than to barrel over the UK...

http://www.wetterzentrale.de/pics/Recm2402.gif

Darren, I removed my post as I think I had posted the wrong chart.  As a liker of cold weather now and again in winter, and a touch of something seasonal, I am feeling more upbeat about the output again today.  I am strapping myself in for something of a roller coaster ride.  Its best to remember that FI starts at around 144/120.  But it does appear to be some form of game on, possibly.

It's not pessimism, rather a realism bred by many years of broken promises.

The majority of posters here have seen too many 'fantasy' patterns develop only to dissolve away in a warm Atlantic breeze to be taken in by a few glimpses of a decent cold set-up. Having said that, there are a few signals that something may be happening - take last nights +240 chart from GFS for instance. It was so screwed-up it sometimes signals a big pattern change is being toyed with.

Indeed, at this time of year FI may as well be at T+24 sometimes! Of course specifics are absolutely impossible to pin down at this range, but the number of models and runs that are showing a cold plunge on the 26th is most remarkable at this range.

Good to have you back Darren

Interesting operational runs this morning (inc GFSP) but I'd advise people to step through the individual GEFS runs which are available on the Chart viewer: 

http://www.theweatheroutlook.com/twodata/datmdlout.aspx

PS: i'm not discounting a cold spell - see homepage - but these aren't so exciting.

Good summary. After a bizarre GFS 18z last night everything seems back on track for a post-Christmas cold blast. Plenty time for it to go pear shaped of course and not convinced by the longevity, but interesting charts nonetheless.

I wonder if the METO extended outlook will pick up on this trend in its update this afternoon?

Wise words Brian. Op was certainly the coldest as seen in graph form....

http://www.wetterzentrale.de/pics/MT8_London_ens.png

Hello Mike - I presume you are back in Norway in which case you won't have long to wait for the shovel season

Latest output is encouraging, I think.  Reflected in odds of White Christmas:

Belfast 7/2

Liverpool and Manchester 5/1

Glasgow 9/4

Edinburgh 13/8

I have expected a NW flow, favouring the west coast for wintery precipitation falling!

(These are Betfair prices and exclude commission.  There is also not much available at these prices, just in case anyone was considering putting the mortgage on...)

HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY WEDNESDAY DECEMBER 17TH 2014.

NEXT UPDATE WEDNESDAY DECEMBER 17TH 08:00

THE CURRENT GENERAL SITUATION A strong and mild WSW flow will be maintained across the UK with troughs embedded within the SW and a cold front close to NW Scotland moving SE from tomorrow.

MODELS-2 WEEK HEADLINE Remaining changeable with rain at times especially across the North and West with snow on hills there at times. Temperatures alternating close to or a little above or below average day to day but possibly becoming generally colder later.

THE JET STREAM ENSEMBLE FORECAST The Jet Stream Ensemble forecast shows the flow slowly moving South to lie South of the UK post Christmas as pressure rises over the Atlantic and to the NW temporarily.

GFS OPERATIONAL The GFS operational this morning shows shows signs of a pattern change as we leave Christmas and enter the period up to the New Year. Until then it is shown to be business as usual with alternating periods of mild and dam weather with colder and more showery periods, these most prolific across the North with wintry showers. Towarsd the end of the run including the New Year it looks like being quite cold under a Northerly bias with wintry showers for all even in the South and widespread night frost before less cold and wet conditions cross SE in the first days of New Year.

THE GFS PARALLEL RUN The GFS Parallel run too shows a similar evolution to the operational with a stronger North flow post Christmas with strong and cold NNW winds and snow showers rattling down across the UK with night frost before higher pressure slipping in from the West and NW deliver cold and frosty weather at the end of the period.

THE GFS CONTROL The GFS control run shows a less bullish show of colder weather post Christmas keeping the influence of a cold NW flow to a minimum before High pressure reasserts itself to the South of the UK and mild SW winds affecting the UK with rain at times in the run up to the New Year.

THE GEFS ENSEMBLES The GEFS Ensembles members heave shifted at least in part to indicate a shift towards a colder snap soon after Christmas as Low pressure enters Scandinavia and pressure rises North through the Atlantic. At this stage this surge of cold isn't shown to last too long as milder West winds in a default position of High to the South and Low to the North into the New Year.

UKMO UKMO today shows the UK under a strong Westerly or SW flow to start next week lying between High pressure to the South and Low to the North. Taking us until Tuesday the weather will be cloudy and mild with some rain at times in a blustery WSW wind.

THE FAX CHARTS The Fax Charts today show a complex series of troughs crossing East and later SE over the UK with a mild ad string WSW flow turning to a colder NW 'ly over the start of the weekend before mild and strong Westerly winds return for Sunday.

GEM GEM also maintains a mild Westerly flow predominating across the UK until Christmas with a brief colder incursion with showers at the start of this coming weekend. Later in the run and over the Christmas period the weather will turn colder as Northerly breezes sweep South with some snow showers in exposed locations facing North principally near Western, Northern and Eastern coasts.

NAVGEM NAVGEM maintains the strong Westerly flow often mild and cloudy with rain mixed with some short 24-48hr periods of brighter and colder weather when wintry showers could occur across the hills of the North primarily at the start to this coming weekend and again over Christmas.

ECM ECM this morning doesn't really engage the cold weather across the UK at Christmas due to deepening Low pressure areas sweeping strong winds and rain across the UK with any cold weather with snow on hills lying on the Northern side of depressions over Southern Britain. Up until this point the pattern of mild and cloudy weather with rain at times prevails with a colder incursion briefly at this weekend.

ECM ENSEMBLES The ECM Ensembles this morning finally indicate a strong chance of a pattern shift as we come out of Christmas and beyond as the mild WSW flow between High pressure to the South and Low to the North finally changes to a strong rise of pressure over the NW Atlantic and Greenland sending a lot of members into Winter mode under Northerly winds with snow showers in places and frost at night.

NOTABLE TREND CHANGES FROM PREVIOUS RUNS Trends this morning have shown their strongest indication of a pattern change afoot as the Azores High becomes less influential as pressure rises to the west and perhaps NW with a stronger dig of cold North winds at least for a time likely post Christmas.

MY THOUGHTS I have to say that I feel more encouraged this morning that a change in the weather is on the way albeit too late for Christmas and may not produce too much excitement for the South of the UK. The basic current pattern will be maintained up to Christmas with rain at times and milder air alternating with brief colder airmasses coming down from the NW. Most models show a marked cold front crossing SE over Christmas introducing a more substantial shot of cold air as pressure rises to the West and NW. It has to be noted though not all models support this view with some returning to a default status to that we have become accustomed to of late returning before the NEW Year. ECM does show colder weather coming into the mix around the UK but the induction of deep Low pressure areas over the UK hinder cold with gales and heavy rain shown post Christmas. The ECM Ensembles are much more encouraging than of late with a biased support of a Northerly flow likely as we leave Christmas and move towards the NEW Year with the all important rise of pressure shown to the West and NW. As is usual we are likely to see major shifts in outcomes within further runs over the coming days, both ebbing and flowing with regard to colder conditions but it does indicate that something is afoot in the models this morning and despite cross model differences there is some common ground between them all. So although it is still a way off I'm sure there are many folk who are looking for cold and snow who will raise their eyebrows with interest from the current set of output this morning.

Would you credit it no sooner do I bang on about this only being a cold snap with the Azores High flattening the pattern out thereafter, then  we see all of the models firm up on a potential cold spell. Still until its at +72  I won't get carried away just yet, although for my location it's looking very snowy with the potential for blizzard conditions. Right ramp over and what about that Azores High.

Many of us battle hardened model watchers are waiting for how this one goes Pete Tong. Easterlies tend to go pear shaped more easily though. I fear we will see horrible shortwaves appearing in the runs soon.

As Ian B says "The train is coming only when you can see the train"

Interesting charts about this morning 

Too early however for wintry weather enthusiasts to order up the open top bus. 

No doubt though about there being some nail-biting chart watching over the next week.

Agreed Mike but has some very close support it has to be said